This invention relates to devices for comminuting materials and particularly relates to an improved impeller for use in a comminuter to impart orbital motion to the material being comminuted.
There are many different types of machines known in the industry for comminuting different types of materials. One such comminuter is the type shown in U.S. Pat. No. 4,366,928 to John H. Hughes, issued Jan. 4, 1983. in the comminuter shown in the Hughes patent, a plurality of upright rollers are arranged to form a comminuting chamber of essentially tubular shape. The material to be comminuted is fed into the upper end of the comminuting chamber and the comminuting action is promoted by orbital movement of the comminuting material about the interior of the comminuting chamber. The centrifugal force of the orbiting material brings the material into contact with the toothed surfaces of the comminuting rollers, which tear and cut the material into smaller particles. Typically, an impeller has been used at the lower end of the comminuting chamber to assist in imparting orbital motion to the materials and, in some cases, the impeller is driven independently of the rolls. In other cases, the impeller is mounted for free rotation and the comminuting rolls are driven so that they impart the motion to the material, when then is maintained in an agitated state by action of the impeller blades.
Although the comminuter of the type shown in the Hughes patent has proved to be an efficient and entirely adequate means for comminuting materials into desired particle sizes, it is an object of the present invention to provide an improved impeller that allows greater and more efficient forces to be brought to bear upon the solid material being comminuted and to more effectively handle the varying sizes of material entered into the comminuting chamber. It is also an object of the invention to provide a comminuter that is more energy efficient and requires a minimum of power to comminute even hard materials.